Field of the Invention
The embodiments of the present invention relate to an apparatus and method for shrinking a fabric, and more particularly, the embodiments of the present invention relate to an apparatus and method for pre-shrinking a wet fabric prior to drying.
Description of the Prior Art
Garment producers and other manufactures are continuously trying to lower acceptable standards of shrinkage in 100% cotton and cotton/synthetic blended fabrics and apparel. Typically, a finished fabric standard of not more than −5% length x −5% width is allowable, and further typically, finished garment shrinkage standards usually are not more than −8% length x −8% width.
These results can be obtained with proper knitting and finishing processes. Now, the standards for garments and apparel are being lowered to −3% to −4% length shrinkage x−3% to −4% width shrinkage by several major U.S. producers.
Fabric producers are unable to obtain the finished fabric shrinkage results to meet these standards without chemical fixation, through the use of resins. Many resins are, however, objectionable from a cost stand point, as well as health concerns because certain resins have been shown to produce cancer. Further, mechanical compaction of the fabric reduces the lengthwise shrinkage of the fabric without chemicals, but the new standards cannot be met by the prior art.
Numerous innovations for compressively treating fabrics have been provided in the prior art, which will be described below in chronological order to show advancement in the art, and which are incorporated herein in their entirety by reference thereto. Even though these innovations may be suitable for the specific individual purposes to which they address, nevertheless, they differ from the embodiments of the present invention in that they do not teach an apparatus and method for pre-shrinking a wet fabric prior to drying.
U.S. Pat. No. 3,015,145—issued to Cohn et al. on Jan. 2, 1962 in U.S. class 26 and subclass 18.6—teaches a method of compressively treating fibrous web material, which includes the steps of feeding the material in a positive manner and at a first predetermined uniform speed substantially to an entry line of a treating zone by closely confining both principle surfaces of the material to a predetermined path during the feeding, discontinuing the positive feeding and the close confining substantially at the entry line, retarding the material to a second predetermined uniform speed at an exit line of the treating zone, whereby the material is caused to decelerate and decreases in length and thereby increases in thickness in passage through the zone, and subjecting the material to heat and substantial localized pressure at the exit line of the treating zone. The increased thickness of the material is substantially greater than that of the predetermined path, whereby decelerating portions of the fabric are confined substantially to the treating zone. The predetermined path is of a length several times larger than the length of the treating zone.
U.S. Pat. No. 4,562,627—issued to Milligan on Jan. 7, 1986 in U.S. class 26 and subclass 18.5—teaches a process for finish drying of tubular knitted fabrics from a wet condition to a substantially finished form in a single process. Wet treated and mechanically extracted fabric is significantly overspread laterally as it enters the upstream end of the dryer, and although already wet, the fabric is steamed. Thereafter, and throughout most of its travel through the dryer system, the fabric is handled to avoid stitch tension to the greatest possible extent, while the wet fabric is assuming geometric stability. The discharged fabric is virtually finished and ready for the cutting table. Mechanical roller compacting of fabrics in a wet condition enables the wet-compacted fabric to be dried to a substantially finished condition without significant loss of its compacting.
U.S. Pat. No. 4,882,819—issued to Milligan et al. on Nov. 28, 1989 in U.S. class 26 and subclass 18.6—teaches a method for compressive lengthwise shrinking of tubular knitted fabrics and other materials, particularly, in a single stage. Feeding and retarding rollers are separated from each other by a distance significantly greater than the thickness of the fabric. Zone-forming blades are projected between the rollers from opposite sides and form therebetween a confinement zone that extends at a large angle from the feeding roller to the retarding roller. Fabric is guided to the zone under low contact pressure by the feeding roller and is conveyed away from the zone under similarly low contact pressure by the retarding roller. At the entrance to the zone, the fabric is decelerated and compacted lengthwise without burnishing or abrasion and without crimping. Tubular and open width knitted fabrics can be compressively pre-shrunk in large amounts up to 25% and more in a single stage.
U.S. Pat. No. 5,016,329—issued to Milligan et al. on May 21, 1991 in U.S. class 26 and subclass 18.5—teaches an apparatus for compressive lengthwise shrinking of tubular knitted fabrics and other materials, particularly, in a single stage. Feeding and retarding rollers are separated from each other by a distance significantly greater than the thickness of the fabric. Zone-forming blades are projected between the rollers from opposite sides and form therebetween a confinement zone that extends at a large angle from the feeding roller to the retarding roller. Fabric is guided to the zone under low contact pressure by the feeding roller and is conveyed away from the zone under similarly low contact pressure by the retarding roller. At the entrance to the zone, the fabric is decelerated and compacted lengthwise without burnishing or abrasion and without crimping. Tubular and open width knitted fabrics can be compressively pre-shrunk in large amounts up to 25% and more in a single stage.
U.S Pat. No. 6,047,483—issued to Allison et al. on Apr. 11, 2000 in U.S. class 34 and subclass 128—teaches a heating system for a mechanical compressive shrinkage apparatus in which a continuously flowing liquid heat-exchange medium is caused to flow in series through each of the components required to be heated. Heat is inputted to the flowing medium in accordance with the temperature of one of the components to be heated, preferably, the first in the series. Uniformity and constancy of both absolute and relative temperatures of the series-connected components is achieved. A mixture of water and propylene glycol alcohol is the heat-exchange medium that allows operation at lower pressure without the maintenance problems of a system using, for example, oil as the exchange medium.
U.S. Pat. No. 6,681,461 B1—issued to Catallo on Jan. 27, 2004 in U.S. class 26 and subclass 18.6—teaches a method and apparatus for shrink-proofing a fabric, typically, a knitted textile composed of interlocked loops of yarn made of at least one of natural and man-made fibers. The loops interlock along stitch rows that may become skewed. The fabric is confined from expanding as it is delivered to, and discharged from, an in-line compression zone free of obstructions, such as, one of crimps, bends, and kinks. The fabric is confined, preferably, resiliently coming to, passing through, and leaving, the compression zone so as to accommodate variations of thickness and irregularities of the fabric being compacted in the compression zone. The interlocked loops are organized, whereby they are allowed to move toward each other orthogonally along their related stitch row so as to reduce volume of the fabric. Non-woven textiles, papers, papers with additives, and the like are shrink-proofed in the same manner.
U.S. Pat. No. 8,590,122 B2—issued to West et al. on Nov. 26, 2013 in U.S. class 26 and subclass 18.6—teaches a two-stage process and apparatus for compacting tubular knitted fabrics. At each stage, the fabric is acted upon by cooperating feeding and retarding rollers that are spaced-apart a distance greater than the thickness of the fabric. Thus, opposite fabric sides cannot be in simultaneous contact with the feeding and retarding rollers at the same point along the fabric. Fabric is transferred from the feeding roller to the retarding roller, while opposite sides of the fabric are closely confined in a compacting zone, free of contact with either roller. Fabric is longitudinally compacted during its traverse of that zone. In the second stage, the rollers are reversely oriented with respect to the fabric. Not more than 60% of the compacting effort is imparted in either one of the stages. Preferably, each stage imparts about 50% of the compacting effort.
It is apparent that numerous innovations for compressively treating fabrics have been provided in the prior art, which are adapted to be used. Furthermore, even though these innovations may be suitable for the specific individual purposes to which they address, nevertheless, they would not be suitable for the purposes of the embodiments of the present invention as heretofore described, namely, a method and apparatus for pre-shrinking a wet fabric prior to drying.